1. Will Rooney being named captain affect Robin van Persie?

The de facto captain now for a few seasons, Wayne Rooney was handed the armband for a second successive game before the announcement that he would occupy the role permanently.

Rooney would have known before the 2-1 win of his promotion so the display he produced, which was below the high standard set in the five friendlies played in America, will have disappointed.

But what intrigues now is how – if at all – Robin van Persie may react to being overlooked for the position. The big debate had centred on whether the manager would plump for Van Persie, whom he elected as Holland captain, and, if so, how might Rooney react to this.

Now the scenario has turned round: could Van Gaal’s self-declared off-field friend react adversely? He is surely too professional …

2. United have serious injury worries

This final pre-season friendly – and Van Gaal’s inaugural match as manager at Old Trafford – began with the 63-year-old stating before kick-off: “We have a lot of injuries but it’s also a chance for the younger boys. We have a lot of injuries and it is not good.”

With Rafael da Silva, Danny Welbeck, Antonio Valencia and Michael Carrick all continuing their recovery from injuries, the sight of the freshly injured Luke Shaw and Jonny Evans watching from the stands was not what Van Gaal needed, especially after declaring Shaw as “not fit” during the tour of America.

As Robin van Persie was also not deemed in adequate condition to be included – Marouane Fellaini and Adnan Januzaj, other late-returning World Cup players were – Van Gaal has a considerable headache before Swansea City’s visit on Saturday.

3. The need to improve

Van Gaal branded this the “worst” display of his six matches in charge and will have returned to his hotel suite pondering what display his chosen XI can offer on Saturday.

Throughout the match United were as tepid as they have been under Van Gaal and managed only two chances in the opening 45 minutes before livening up a little after the break.

The first was a weak Phil Jones header that Diego Alves collected easily, the second a dubious penalty won by Rooney, who then struck it against the right post.

Darren Fletcher may have scored a scrappy goal before Fellaini’s last-gasp winner but United remain a work in progress.

In the pre-game notes Van Gaal said: “I wanted to see an improvement in our performances as the [US] tour went along and that was mainly the case. In the first half of the match against Liverpool I must say that we were very weak but the spirit of the team turned that around, the players wanted to show themselves as a team and that is very important to me.”

That heart again pulled the side through against an unimpressive Valencia but more is required once the season begins.

The jury remains out on Ashley Young and the absent Antonio Valencia as wingbacks, with the former asked to play on the right after being deployed mainly on the left during the tour. The big question hovering over Young and Valencia is that, whatever misgivings Van Gaal might have about their attacking prowess, are they up to it defensively?

Although Shaw and Da Silva can be expected to fill this requirement, they are doubts for Saturday and Van Gaal wants both to show better form than they have done. So the manager’s push to sign Sporting Lisbon’s Marcos Rojo, a left-sided defender of pace and vast international experience – he played all 120 minutes of Argentina’s World Cup final defeat – is explained.

Further ahead in the formation Carrick was missing, forced to watch having arrived at Old Trafford on crutches. With Van Gaal still hoping to land a central midfielder, how he must wish Carrick had not injured his ankle ligaments just as he took over last month. Ander Herrera buzzed around the pitch showing impressive flashes and Fletcher scored but they missed Carrick, who can control the tempo and switch the flow of a game with a sweeping pass.

5. Might Hobson’s choice give youth a chance?

The fitness issues documented above meant Reece James started at left wing-back for Shaw and Tyler Blackett was one of the three centre-backs in place of Evans. As James and Blackett, who are both 20, showed during the tour of America, they may have a chance at this level but Van Gaal does not believe consistent performances can be produced at the moment.

The manager said: “It’s a chance for the younger boys and that’s good I think. They did well in the United States, so I’m also curious tonight to see what they do.” Both returned tidy performances, lasting the full 90 minutes to give Van Gaal more to consider. And, as the manager waits to discover who will be fit for Saturday, he may be forced into some hardly ideal decisions.